Observaciones del manto de nieve durante una circunnavegación del casquete de hielo de Groenlandia (primavera de 2014)

Abstract

We report the characteristics of the Greenland ice sheet snowpack, based on data collected during the first wind-propelled circumnavigation of the ice sheet, undertaken in spring 2014. The dataset included snow depth measurements made in 100 m2 plots, and data on the snow bulk density and snowpack temperature at 1 m depth at 25 sites distributed along the 4301 km route traveled during the 49 days of the circumnavigation. In addition, eight snow pits of 1 m depth were dug to measure the snow temperature and density at 10 cm intervals in the upper layer of the snowpack. All this information may help to better understand snow characteristics on this remote area, and provide data to validate and calibrate atmospheric and cryospheric models.Snow depths exceeding 4 m were measured in the snow accumulation area, but in many cases the presence of an ice layer prevented penetration of the snow probe below 70 cm depth. This ice layer may be associated with the melting event that occurred in July 2012, and affected 98% of the ice sheet. Beyond the main snow accumulation zone, very constant snow depth values of approximately 1.5 m were measured. The snow temperature at 1 m depth generally ranged from –20°C to –10°C, and was highly correlated with the average atmospheric temperature during the 15 days prior to the snow temperature measurements. The snow bulk density was relatively homogeneous at the majority of sampling sites, ranging from 320 to 390 kg m–3. The snow temperature and density profiles measured in the snow pits indicated that the snowpack became progressively colder from the surface to 1 m depth. The temperature gradient measured in the snow pits was particularly steep (shallow) at the warmest (coldest) sampling sites. The snow density was characterized by denser snow at 60–80 cm depth, coinciding with the depth of the ice layer identified when depth was measured. A dense layer was also found close to the surface at the warmest snow pit sites, and it is likely that this corresponds to a more recent snow melt event.